Amino acid functionalized silicones and method for preparation

ABSTRACT

Organofunctional siloxanes useful in a wide variety of personal care and plastics applications are disclosed having a carboxyalkylaminoalkyl functionality.

The present invention relates to silicones useful in both the personalcare and plastics industries. More particularly, the present inventionrelates to an organofunctional silicone. Most particularly, the presentinvention relates to amino acid functionalized silicones.

BACKGROUND OF THE PRESENT INVENTION

Organofunctional silicones are well known in the art. The siloxane maybe functionalized with substituents such as carboxy, amido, ketoxy,epoxy, vinyl, hydride, mercapto, amino, glycidoxy, methacryloxy andalkoxy groups. These organofunctionalities are generally employed toobtain specific physical and chemical properties. Aminoalkyl-substitutedsilicones, for example, increase water solubility and are used inautomobile polishes to enhance durability and confer detergentresistance through bonding with paint films. Other functionalized fluidsfind use in applications such as textile lubricants, softeners andantistats. A variety of amino functional siloxanes are described in theprior art.

Brumbill, U.S. Pat. No. 4,785,067, teaches a protective coatingconsisting essentially of a polysiloxane copolymer prepared by thereaction of a trimethyl end blocked polyamine silicone fluid includingamino alkyl groups with a saturated aliphatic carboxylic acid groups toproduce a polysiloxane copolymer including alkyl amine groups.

van Hooijdonk, U.S. Pat. No. 5,028,485, teaches a pressure sensitiveadhesive composition suitable for skin contact comprising a silanecompound having at least one amino functional group.

Imperante et al., U.S. Pat. No. 5,115,049, teach the preparation offatty carboxylic acid salts of organofunctional silicone amines, wherethe amino pendant functionality is present within the polymer and whichare produced by the neutralization of a silicone amine with a fattycarboxylic acid.

It has now been found that novel amino acid functionalized silicones canbe produced, and that such compounds are useful in a variety of plasticand personal care applications.

SUMMARY OF THE INVENTION

According to the present invention there is provided an organofunctionalsilicone composition comprising those of the formula: (i) TD_(x) M'₃ ;(ii) TD_(x) D'_(y) M'₃ ; (iii) TD'_(y) M'₃ ; (iv) TD_(x) D'_(y) M₃ ; (v)TD'_(y) M₃ ; (vi) M'D_(x) D'_(y) M'; (vii) M'D_(x) M'; (viii) MD'_(y) M;(ix) MD_(x) D'_(y) M; (x) M'D'_(y) M'; (xi) M'Q; (xii) (D')_(z) ; or(xiii) a combination of any of the foregoing; wherein T represents atrifunctional siloxy group of the formula RSiO_(3/2) wherein Rrepresents a saturated or unsaturated monovalent hydrocarbon radical; Drepresents a difunctional siloxy group of the formula R₂ SiO_(2/2)wherein each R is independently defined as above; D' represents adifunctional siloxy group of the formula RR¹ SiO_(2/2) wherein each R isindependently defined as above, R¹ is a carboxyalkyl aminoalkyl group ofthe formula (HO₂ C)(CH₂)_(m) N(R²)(CH₂).sub. n where R² representshydrogen or an alkyl group of from 1 to 10 carbon atoms, and m and neach independently vary from 1 to 10; M represents a monofunctionalsiloxy group of the formula R₃ SiO_(1/2) wherein each R is independentlydefined as above; M' represents a monofunctional siloxy group of theformula R₂ R¹ SiO_(1/2) wherein each R is independently defined as aboveand R¹ is as above defined; Q represents a quadrifunctional siloxy groupof the formula SiO_(4/2) ; x is greater than 1, y is greater than 1 andz is equal to or greater than 3.

Also according to the present invention there is provided a process forpreparing the amino acid functionalized silicones of the presentinvention comprising the steps of: (a) hydrosilating a silicone hydridecompound with a lactam to form an amide functionalized silicone; and (b)hydrolyzing the amide functionalized silicone of step (a) to produce anamino acid functionalized silicone.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

The novel amino acid functionalized silicones of the present inventionare generally prepared by hydrosilating the appropriate linear, branchedor cyclic silicone hydride with a lactam and then hydrolyzing the lactamfunctionalized silicone to produce the amino acid functionalizedsilicones of the present invention.

The silicone hydrides for use in the practice of the present inventionare typically those which correspond to the product amino acidfunctionalized siloxanes, and are generally selected from TD_(x) M"₃ ;TD_(x) D"_(y) M"₃ ; TD"_(y) M"₃ ; TD_(x) D"_(y) M₃ ; TD"_(y) M₃ ;M"D_(x) D"_(y) M"; M"D_(x) M"; MD"_(y) M; MD_(x) D"_(y) M; M"D"_(y) M";M"Q; (D")_(z) ; or combinations of any of the foregoing where M" is amonofunctional siloxy hydride of the formula (R)₂ (H) SiO_(1/2) ; D is adifunctional siloxy hydride of the formula (R)(H)SiO_(2/2) and T, D, M,Q, R, x, y, and z are as defined hereinabove. The siloxy hydrides areavailable commercially and can be prepared by methods known to thoseskilled in the art.

The lactams useful in the present invention for the hydrosilationreaction are generally of the formula ##STR1## wherein R³ is an alkenylgroup of from 2 to about 10 carbon atoms and q is an integer rangingfrom 1 to about 10. A preferred lactam for use in the practice of thepresent invention is n-vinyl pyrrolidone, wherein R³ is vinyl, and q is2 in the above formula.

The lactam is generally reacted with the appropriate silicone hydride byhydrosilation techniques well known to those of ordinary skill in theart. In general the hydrosilation reaction proceeds in the presence of aGroup VIII precious metal complex, i.e. platinum, rhodium and/orruthenium complexes. Such catalyst complexes are well described in thepatent literature, e.g., Karstedt, U.S. Pat. No. 3,775,452; Ashby etal., U.S. Pat. No. 4,288,345; Bailey et al., U.S. Pat. No. 3,336,239;Ashby, U.S. Pat. No. 4,421,903; Lamoreaux, U.S. Pat. No. 3,220,972; andLewis, U.S. Pat. No. 4,946,818. See also, J. Organometallic Chem. 408(1991) pp. 297-304. A preferred catalyst for use in the presentinvention comprises tris(dibutylsulfide) rhodium trichloride.

The lactam modified siloxanes are then reacted in a hydrolysis reactionaccording to techniques known to those skilled in the art. Typically,the hydrolysis reaction is conducted in the presence of an acid, such asdilute sulfuric acid. However, other acids may be employed. Thehydrolysis reaction acts to open the amine ring structure to give thecorresponding acid. The product is an amino acid functionalizedsiloxane.

The organofunctional siloxanes of the present invention may be branched(T or Q), linear (D) or cyclic ([D]_(z)) . They are of the generalformulae: (i) TD_(x) M'₃ ; (ii) TD_(x) D'_(y) M'₃ ; (iii) TD'_(y) M'₃ ;(iv) TD_(x) D'_(y) M₃ ; (v) TD'_(y) M₃ ; (vi) M'D_(x) D'_(y) M'; (vii)M'D_(x) M'; (viii) MD'_(y) M; (ix) MD_(x) D'_(y) M; (x) M'D'_(y) M';(xi) M'Q; (xii) (D')_(z) ; or (xiii) a combination of any of theforegoing. In preferred embodiments, x and y are each independentlygreater than about 1, preferably each independently ranges from about 1to about 1000, and more preferably each ranges from about 1 to about100. In the case of cyclics, z is typically equal to or greater thanabout 3 and preferably varies from about 4 to about 12.

In the above formulae, each R independently represents a saturated orunsaturated monovalent hydrocarbon, typically containing no more thansix carbon atoms and selected from those such as alkyl radicals, e.g.,methyl, ethyl and isopropyl; cycloaliphatic radicals, e.g., cyclopentyland cyclohexenyl; olefinic radicals, e.g., vinyl and allyl; and thephenyl radical.

R¹ represents a carboxyalkyl aminoalkyl group of the formula (HO₂ C)(CH₂)_(m) N(R²)(CH₂)_(n) where R² represents hydrogen or an alkyl group offrom 1 to 10 carbon atoms, and m and n each independently vary from 1 to10. In preferred embodiments, R¹ is selected fromN-(3-carboxypropyl)-aminoethyl; N-(3-carboxybutyl)aminoethyl,N-(3-carboxymethyl)aminopentyl and the like. Particularly useful in thepractice of the present invention is N-(3-carboxypropyl)aminoethyl.

The following reaction scheme depicts the general reaction route forlinear materials reacted with n-vinyl pyrrolidone. ##STR2##

The amino acid functionalized siloxanes of the present invention haveuses in a wide variety of personal care and plastics applications,including but not limited to use as plastic additives, hydraulic fluids,vibration damping, release agents. antifoamers, dielectric media, waterrepellents, surfactants, greases, coagulants, cosmetic and healthproduct additives, heat transfer media, polishes, lubricants, etc.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following examples illustrate the present invention. They are not tobe construed to limit the scope of the appended claims in any mannerwhatsoever.

EXAMPLE 1

25.8 g of n-vinyl pyrrolidone and 119 g of toluene were azeotroped for1.5 hours. The temperature was cooled to 100° C. and one drop oftris(dibutylsulfide) rhodium trichloride catalyst was added. 106.1 g ofa branched siloxane of the general formula TD₁₅ M^(H) ₃ where M^(H)represents a dimethyl hydride siloxane of the formula (CH₃)₂ HSiO_(1/2)is then slowly added. After the addition, the reaction was maintained atreflux. After one hour, an infrared spectrum indicated that the hydridewas still present. Two more drops of the catalyst were then added untilthe hydride band had disappeared. The infrared spectroscopy of thissolution indicated that the alkene had disappeared and that the carbonylhad shifted to 1684 cm⁻¹.

Five grams of a dilute sulfuric acid solution were then added to themixture. While refluxing, a black solid deposited on the glass surface.After 2.5 hours, another 20 g of water was added and the entire mixturewas allowed to stir for one more hour. The liquids were removed undervacuum to afford an amino acid functional siloxane oil of the presentinvention which had a broad carbonyl band between 1736 cm⁻¹ and 1619cm⁻¹.

EXAMPLE 2

49.2 g of M^(H) M^(H) siloxane and 189 g of toluene were azeotroped.Three drops of the tris(dibutylsulfide) rhodium trichloride catalystwere then added followed by the slow addition of 81.4 g of n-vinylpyrrolidone. The mixture was allowed to stir for 3 hours at 100° C.whereupon 10 more drops of the catalyst were added due to indicationthat the reaction had not proceeded. Within an hour, infraredspectroscopy indicated the reaction was complete. A small portion ofthis solution was removed, filtered through celite and rotoevaporatedusing a vacuum pump to isolate the n-vinyl pyrrolidone adduct. 32.5 g ofoil was isolated. IR¹⁶⁸⁴ cm⁻¹ ; NMR CDCl₃ standard: 0.05 ppm s,s 12H(Me-Si), 1.09 m 4H (CH₂ - Si), 2.00 m 4H (CH₂), 2.25 m 4H (CH₂), 3.27 m4H (CH₂ -N), 3.41 m 4H (CH₂ -N). The NMR assignments are based on thealpha-alpha adduct and comparison of spectra of various substitutedpyrrolidones. See, Bovey, F. A., "NMR Data Tables for OrganicCompounds", Interscience Publishers, 1967, V.1.

To the remainder of the mixture, was added 40 ml of water whichcontained 4 drops of sulfuric acid. The mixture was heated at 90° C. forone hour and then allowed to cool. The mixture was then extracted withtoluene, the organic layer subsequently being dried over sodium sulfateand rotoevaporated to afford 67 g of an amino acid functionalizedsiloxane oil of the present invention. IR1678 cm⁻¹ broad. NMR CDCl₃standard: 0.00 ppm s,s 12H (CH₃ -Si); 1.02 m 4H (CH₂ -Si), 1.82 m 4H,2.19 m 4H, 3.25 m 4H and 3.36 m 4H.

The above-mentioned patents and publications are all hereby incorporatedby reference.

Many variations of the present invention will suggest themselves tothose skilled in the art in light of the above-detailed description.Other siloxanes may be employed in the present invention, includingTD_(x) D'_(y) M'₃, TD'_(y) M'₃, TD_(x) D'_(y) M₃, TD'_(y) M₃, M'D_(x)M', MD'_(y) M, MD_(x) D'_(y) M, M'D'_(y) M', M'Q and (D')_(z) may all beemployed in the present invention. Further, a wide variety of lactamsother than n-vinyl pyrrolidone are contemplated for use in the presentinvention. All such obvious modifications are within the full intendedscope of the appended claims.

We claim:
 1. A method of preparing an organofunctional siliconecomposition comprising units of the formula

    ______________________________________                                                  (i)  TD.sub.x M.sub.3 ';                                                      (ii) TD.sub.x D.sub.y 'M.sub.3 ';                                             (iii)                                                                              TD.sub.y 'M.sub.3 ';                                                     (iv) TD.sub.x D.sub.y 'M.sub.3 ;                                              (v)  TD.sub.y 'M.sub.3 ;                                                      (vi) M'D.sub.x D.sub.y 'M';                                                   (vii)                                                                              M'D.sub.x M';                                                            (viii)                                                                             MD.sub.y 'M;                                                             (ix) MD.sub.2 D.sub.y 'M;                                                     (x)  M'D.sub.y 'M';                                                           (xi) M'Q;                                                                          or                                                             ______________________________________                                    

(xiii) a combination of any of the foregoing wherein T represents atrifunctional siloxy group of the formula RSiO_(3/2) wherein Rrepresents independently a saturated or unsaturated monovalenthydrocarbon radical; D represents a difunctional siloxy group of theformula R₂ SiO_(2/2) wherein each R is independently defined as above;D' represents a difunctional siloxy group of the formula RR¹ SiO_(2/2)wherein each R is independently defined as above, R¹ represents acarboxyalkyl aminoalkyl group of the formula (HO₂ C)(CH₂)_(m)N(R²)(CH₂)_(n) where R² represents hydrogen or an alkyl group of from 1to about 10 carbon atoms, and m and n each independently vary from 1 toabout 10; M represents a monofunctional siloxy group of the formula R₃SiO_(1/2) wherein each R is independently defined as above; M'represents a monofunctional siloxy group of the formula R₂ R¹ SiO_(1/2)wherein each R is independently defined as above and R¹ is as abovedefined; Q represents a quadrifunctional siloxy of the formula SiO_(4/2); x is greater than 1, y is greater than 1 and z is equal to or greaterthan 3; comprising the steps of: (a) hydrosilating a silicone hydridecompound with a lactam to form an amide functionalized silicone whereinsaid lactam contains an alkenyl group and (b) hydrolyzing the amidefunctionalized silicone of step (a) to produce an amino acidfunctionalized silicone.
 2. A process as defined in claim 1 wherein saidsilicone hydride is selected from TD_(x) M"₃ ; TD_(x) D"_(y) M"₃ ;TD"_(y) M"₃ ; TD_(x) D"_(y) M₃ ; TD"_(y) M₃ ; M"D_(x) D"_(y) M"; M"D_(x)M"; MD"_(y) M; MD_(x) D"_(y) M; M"D"_(y) M"; M"Q; or combinations of anyof the foregoing where M" is a monofunctional siloxy hydride of theformula (R)₂ (H)SiO_(1/2) ; D" is a difunctional siloxy hydride of theformula (R)(H)SiO_(2/2) and T, D, M, Q, R, x, y, and z are as definedabove.
 3. A process as defined in claim 1 wherein said lactam has thegeneral formula ##STR3## wherein R³ is an alkenyl group of from 2 to 10carbon atoms and q is an integer ranging from 1 to about
 10. 4. Aprocess as defined in claim 3 wherein R is a vinyl group, q is 2 and thelactam is n-vinyl pyrrolidone.
 5. A process as defined in claim 1wherein the hydrosilating step (a) is carried out with a catalystselected from a rhodium catalyst or a platinum catalyst.
 6. A process asdefined in claim 1 wherein the hydrolyzing step (b) is carried out witha dilute sulfuric acid.
 7. An organofunctional silicone compositionprepared by the process as defined in claim 1.